First of all, How much are you wiling to spend on fish? and If you have the money and you're looking for Bright colors then may I suggest discus? Maybe over time build up a planted tank? That tank looks amazing for a planted. Maybe have a Large fish community? with some blood parrots or angels or (Like I said) Discus with some bottom feeders like loaches, Synodontis' and maybe have some large schooling fish like congos? This is something like I'm doing with my brand new 70g, Large fish. Have you ever thought about African cichlids? You'd probably have to change your substrate and driftwood to rocks to make it look natural which I'm guessing you don't want? The possibilities are endless man tell me if you're interested in some of the things I've said or if you want some more ideas